1. Field of the Invention
This invention relates to data recording, and more particularly to apparatus and methods for providing end-to-end data protection while supporting multiple CRC algorithms.
2. Background of the Invention
End-to-end data protection is a feature that extends error detection to cover the entire path from a computer system (i.e., a host system) to a storage device (e.g., a hard drive) and back again to a computer system. This feature generally involves appending data protection information (e.g., CRCs) to data at the originating computer system. This data protection information then travels with the data from the computer system to the storage device along any intervening data path. Before writing the data to underlying storage media, the storage device may check the integrity of the data using the attached data protection information. If the integrity is good, the storage device may then write the data and data protection information to the storage media. When the same data is read from the storage media, the storage device may recheck the integrity of the data using the data protection information and, if the integrity is good, return the data and accompanying data protection information to the computer system.
Currently, the ANSI T10 standard defines a way to check the integrity of data travelling from a host device to a tape drive and back again through a data path such as a SAN fabric. The check is implemented through an appended CRC and is called logical block protection defined in the T10 standard. Nevertheless, the T10 standard does not take into account different algorithms (e.g., different CRC algorithms) that may be used to generate data protection information. For the data protection information to effectively protect the data, the same algorithm needs to be used by the various components (e.g., computer system, storage device, network components) along the data path. Current standards do not provide a way to effectively coordinate the use of multiple data protection algorithms.
In view of the foregoing, what are needed are apparatus and methods to provide end-to-end data protection on storage media such as magnetic tape. Ideally, such apparatus and methods will provide an additional marketing tool to convince users to adopt tape as a reliable, cost-effective data storage technology. Further needed are apparatus and methods to coordinate the use of multiple data protection (e.g., CRC) algorithms when providing end-to-end data protection.